Remove grace period logic and improve meeting deactivation

- Removed grace_period_minutes and last_participant_left_at fields
- Simplified deactivation logic based on actual usage patterns:
  * Active sessions: Keep meeting active regardless of scheduled time
  * Calendar meetings: Wait until scheduled end if unused, deactivate immediately once used and empty
  * On-the-fly meetings: Deactivate immediately when empty
- Created migration to drop unused database columns
- Updated tests to remove grace period test cases

server/tests/test_multiple_active_meetings.py

@@ -117,69 +117,6 @@ async def test_get_active_by_calendar_event():
     assert found_meeting.calendar_event_id == event.id
 
 
-@pytest.mark.asyncio
-async def test_grace_period_logic():
-    """Test that meetings have a grace period after last participant leaves."""
-    # Create a room
-    room = await rooms_controller.add(
-        name="test-room",
-        user_id="test-user",
-        zulip_auto_post=False,
-        zulip_stream="",
-        zulip_topic="",
-        is_locked=False,
-        room_mode="normal",
-        recording_type="cloud",
-        recording_trigger="automatic-2nd-participant",
-        is_shared=False,
-    )
-
-    current_time = datetime.now(timezone.utc)
-    end_time = current_time + timedelta(hours=2)
-
-    # Create meeting
-    meeting = await meetings_controller.create(
-        id="meeting-grace",
-        room_name="test-meeting-grace",
-        room_url="https://whereby.com/test-grace",
-        host_room_url="https://whereby.com/test-grace-host",
-        start_date=current_time,
-        end_date=end_time,
-        user_id="test-user",
-        room=room,
-    )
-
-    # Test grace period logic by simulating different states
-
-    # Simulate first time all participants left
-    await meetings_controller.update_meeting(
-        meeting.id, num_clients=0, last_participant_left_at=current_time
-    )
-
-    # Within grace period (10 min) - should still be active
-    await meetings_controller.update_meeting(
-        meeting.id, last_participant_left_at=current_time - timedelta(minutes=10)
-    )
-
-    updated_meeting = await meetings_controller.get_by_id(meeting.id)
-    assert updated_meeting.is_active is True  # Still active during grace period
-
-    # Simulate grace period expired (20 min) and deactivate
-    await meetings_controller.update_meeting(
-        meeting.id, last_participant_left_at=current_time - timedelta(minutes=20)
-    )
-
-    # Manually test the grace period logic that would be in process_meetings
-    updated_meeting = await meetings_controller.get_by_id(meeting.id)
-    if updated_meeting.last_participant_left_at:
-        grace_period = timedelta(minutes=updated_meeting.grace_period_minutes)
-        if current_time > updated_meeting.last_participant_left_at + grace_period:
-            await meetings_controller.update_meeting(meeting.id, is_active=False)
-
-    updated_meeting = await meetings_controller.get_by_id(meeting.id)
-    assert updated_meeting.is_active is False  # Now deactivated
-
-
 @pytest.mark.asyncio
 async def test_calendar_meeting_force_close_after_30_min():
     """Test that calendar meetings force close 30 minutes after scheduled end."""
@@ -232,52 +169,3 @@ async def test_calendar_meeting_force_close_after_30_min():
 
     updated_meeting = await meetings_controller.get_by_id(meeting.id)
     assert updated_meeting.is_active is False  # Force closed after 30 min
-
-
-@pytest.mark.asyncio
-async def test_participant_rejoin_clears_grace_period():
-    """Test that participant rejoining clears the grace period."""
-    # Create a room
-    room = await rooms_controller.add(
-        name="test-room",
-        user_id="test-user",
-        zulip_auto_post=False,
-        zulip_stream="",
-        zulip_topic="",
-        is_locked=False,
-        room_mode="normal",
-        recording_type="cloud",
-        recording_trigger="automatic-2nd-participant",
-        is_shared=False,
-    )
-
-    current_time = datetime.now(timezone.utc)
-    end_time = current_time + timedelta(hours=2)
-
-    # Create meeting with grace period already set
-    meeting = await meetings_controller.create(
-        id="meeting-rejoin",
-        room_name="test-meeting-rejoin",
-        room_url="https://whereby.com/test-rejoin",
-        host_room_url="https://whereby.com/test-rejoin-host",
-        start_date=current_time,
-        end_date=end_time,
-        user_id="test-user",
-        room=room,
-    )
-
-    # Set last_participant_left_at to simulate grace period
-    await meetings_controller.update_meeting(
-        meeting.id,
-        last_participant_left_at=current_time - timedelta(minutes=5),
-        num_clients=0,
-    )
-
-    # Simulate participant rejoining - clear grace period
-    await meetings_controller.update_meeting(
-        meeting.id, last_participant_left_at=None, num_clients=1
-    )
-
-    updated_meeting = await meetings_controller.get_by_id(meeting.id)
-    assert updated_meeting.last_participant_left_at is None  # Grace period cleared
-    assert updated_meeting.is_active is True  # Still active